| Abstract
| - The molecular structures determine the physical properties of milk proteins and are important for thetexture of many dairy-based foods. Bovine α-lactalbumin (α-LA) is a globular 123 amino acid Ca2+binding milk protein. Modification with microbial Ca2+ independent transglutaminase (MTGase) wasused to modify lysines and glutamines in holo and apo α-LA. At 30 °C no lysines or glutamines aremodified in holo α-LA, whereas in apo α-LA lysines 13, 16, 108, and 114, and glutamines 39 and 43,are modified. At 50 °C lysines 13, 16, 108, and 114, but no glutamines, are modified in holo α-LA,whereas in apo α-LA lysines 5, 13, 16, 108, and 114, and glutamines 39, 43, 54, 65, and 117, aremodified. The methods presented here offer the possibility to manipulate the availabilities of residuesin α-LA to the MTGase reaction and enable the preparation of α-LA species with different degreesof modification and hence with different physical properties. Keywords: Transglutaminase; α-lactalbumin; calcium; mass spectrometry; protein structure
|
